The invention relates to a device for securing railroad rails on a ballast track or a solid track in a highly resilient manner.
Two separate systems exist as devices for securing railroad rails. On the one hand, the attachments for sleepers or supports on a ballast foundation, and on the other hand the superstructure for a solid track, i.e. securing rails for a superstructure without ballast. The superstructure on a solid track is increasingly gaining in important as axle loads and journey speeds rise, whereby as regards the superstructure on a solid track it is essential to achieve a requisite track compression.
Yet ballast tracks which are fitted with the standard superstructure also frequently exhibit rail compression values that are too low for use in high-speed transport on new routes. The resilience of ballast permits track compression which results in a rail head depression of about 0.6 mm. This track compression is clearly below today's desired rail head depression of 1.5 mm.
The resilient intermediate layers used in the prior art, even the use of so-called "soft" intermediate layers with static spring rates of c=50-70 kN/mm, improve track compression only to a rail head depression of about 1.0 mm (in conjunction with the ballast track).
A device for securing railroad rails on a solid track is described in EP 0 295 685. To achieve good track compression, a resilient intermediate plate is disposed between the rail flange and the concrete railroad sleeper; this plate ensures sufficient compression. Above the resilient intermediate plate there is located a pressure distribution plate which is dimensioned such that it and the resilient intermediate plate laterally project above the flange of the rail. Angle guide plates which form a support for tension clamps to secure the rails and which press the same against the rail flange by means of a sleeper screw are arranged on both sides of the rail flange. The guide angle plates form a rail channel, absorb the horizontal forces and introduce them into the concrete sleeper via angled surfaces in contact with the sleeper. The angle guide plates have chamber-like recesses into which the pressure distribution plate (protruding on both sides across the width of the rail flange) and resilient intermediate plate can project. The concrete sleepers described in EP 0 295 685 are specifically adapted to use on a solid track, and in the securing region they have a very low recess that completely receives the angle guide plates.